Toshiba OCZ RD400 M.2 NVMe SSD Review

I/O Performance

There is little point of having an SSD drive that has blazing sustained reading and writing speeds, if the drive can’t handle reading and writing of small random files. If you intend to use your new SSD drive to store and run your operating system, then the drive must be able to cope with the many small random files that Windows will write to the drive continually. So I feel it is very important to test how many of these random files that a drive can handle in one second. I believe that anything over 1,000 I/O’s per second would be enough for most users running a consumer grade mainstream PC, and should provide a smooth running system. But obviously, the more I/O’s that a drive can handle, the faster the drive will feel and leave more headroom for those huge multitasking sessions that users sometimes engage in.

IOMeter is probably the most versatile of all the synthetic benchmarks. Its ability to be configured to generate a multitude of different I/O traffic is unmatched. Another great feature of IOMeter, is the capability to test any storage metric that you can think of, providing you know how to configure the assignments. The reviewer also has complete control over things like queue depth, block size, whether the traffic is random, sequential, or even a mixture of both.

Partition alignment and sector boundaries

Windows 10, Windows 8.1, Windows 7, and Windows Vista will automatically align a partition to 4k boundaries during partition creation, Windows XP won’t. It is imperative that an SSD’s partition is aligned. Windows XP is also restricted to sector boundaries, while Windows 7 and 8 will use 4k boundaries if they can. The Toshiba OCZ RD400 M.2 NVMe SSD is 4k boundary aware, and will use these boundaries if possible. Of course it will also remap LBAs for compatibility with the sector boundaries so that the drive can be used with Windows XP.

IOMeter allows us to set the sector boundaries for conducting the tests, and I have therefore set the sector boundaries at 4K, which means the IOMeter tests are valid for Windows 7, Windows 8, and Windows Vista users. XP users will not be able to obtain such results.

I will provide a screenshot of the tests on the review drive for those of you who like to see the actual test result. All the comparison drive results are represented in the form of graphs.

If any of you would like to see a screenshot from any IOMeter test on a particular drive, please feel free to request one, and I’ll post the screenshot in the forum thread.

All the IOMeter tests create a 10GB data set on the target drive, and each test is run for a duration of 3 minutes.

IOMeter 4K random write test with repeating data.

The first test involves creating continual 4KB random files on the target drive with IOMeter. I use a 4KB file size, as it is believed that Windows will create and modify many of this size of file constantly in the background during a typical Windows session. It is said that most 4K random writes take place at a queue depth of only one, and I have been requested to include this test in my reviews.

Queue depth 1

Toshiba OCZ RD400 M.2 NVMe 512GB SSD – 4K random write (QD 1)

At 236.88 MB/s the Toshiba OCZ RD400 M.2 NVMe SSD’s performance is outstanding, and it finishes this test in third place.

Our next test involves creating continual 4KB random files on the target drive with IOMeter. I use a 4KB file size, as it is believed that Windows will create and modify many of this size of file constantly in the background during a typical Windows session. I will use queue depths of 4 and 32 for these tests.

Queue depth 4

Toshiba OCZ RD400 M.2 NVMe 512GB SSD (QD 4)

At a queue depth of 4, the Toshiba OCZ RD400 M.2 NVMe SSD is outstanding, and finishes this test in second spot.

Queue depth 32

Toshiba OCZ RD400 M.2 NVMe 512GB SSD (QD 32)

Once the Toshiba OCZ RD400 M.2 NVMe 512GB SSD reaches a queue depth of four, there isn’t much more performance to be attained with higher queue depths, when writing small random files. However, at 743.42 MB/s, the Toshiba OCZ RD400 is still performing extremely well, and takes third spot in this test.

IOMeter 4K random write test with fully random data.

This test is exactly the same as the test above except that the test data is fully random and is therefore much more difficult to compress. This test was requested as SandForce based SSDs gain a lot of performance by being able to compress data on the fly. While the above test shows the SandForce based SSDs in a best case scenario, the following test will show the SandForce based SSDs in a much more realistic scenario.

Queue depth 4 with fully random data

The Toshiba OCZ RD400 M.2 NVMe SSD pays no penalty when writing data which is incompressible, and finishes this test in second place.

4K random write queue depth profile

For this test I used various queue depths from 1 – 32 to give you an idea how this SSD performs at different queue depths. For a normal desktop user, with lightweight multitasking, the queue depth will rarely rise above 2. For heavy multitasking, the queue depth is unlikely to rise above a value of 8.

The results are shown below.

As we can see, the Toshiba OCZ RD400 M.2 NVMe SSD has outstanding performance at low queue depths but, after reaching a queue depth of 4, performance doesn’t increase with higher queue depths. One should note, that with this level of performance at low queue depths, the fact that the Toshiba OCZ RD400 M.2 doesn’t really scale well after a queue depth 4 isn’t really a problem.

Below I present a table of the results in greater detail.

Queue depth 32 with four threads (write)

This test is new, and designed to simulate an extremely heavy writing workload, and is unlikely to occur even in a heavyweight consumer computing session. The test is simply to measure the maximum throughput a PCIe NVMe SSD can achieve.

The workload consists of writing 4K random data at a queue depth of 32, and running this workload with four threads.

The Toshiba OCZ RD400 M.2 NVMe SSD is by far the fastest SSD in this test.

IOMeter 4K random read test.

If there are many 4k files created, then that must also mean that many 4k files need to be read. This test measures 4k reading performance.

It is said that most 4K random reads take place at a queue depth of only one, and readers have requested that I include this test in my reviews.

Queue depth 1

Toshiba OCZ RD400 M.2 512GB SSD – 4K random read (QD 1)

In this test the Toshiba OCZ RD400 M.2 NVMe SSD has excellent performance, and finishes in third place.

Queue depth 4

Toshiba OCZ RD400 M.2 NVMe 512GB SSD – 4K random read (QD 4)

At a queue depth of four, the Toshiba OCZ RD400 M.2 NVMe is excellent, and once again is the third fastest SSD in this test.

Queue depth 32

Toshiba OCZ RD400 M.2 NVMe 512GB SSD – 4K random read (QD 32)

At a queue depth of 32, the Toshiba OCZ RD400 M.2 NVMe SSD is showing outstanding performance, and finishes this test in first place.

4K random read queue depth profile.

This test shows how the review drive scales with increasing queue depths.

Below I present a table of the results in greater detail.

Queue depth 32 with four threads (read)

This test is new, and designed to simulate an extremely heavy reading workload, and is unlikely to occur even in a heavyweight consumer computing session. The test is simply to measure the maximum throughput a PCIe NVMe SSD can achieve.

The workload consists of reading 4K random data at a queue depth of 32, and running this workload with four threads.

The result is interesting to say the least. Whilst it’s unlikely that a consumer workload would require this sort of performance, it is still interesting to see that the Toshiba OCZ RD400 can reach 1.107 GB/s, and reach an incredible 270269.08 IOPS.

Let’s compare the results with other recently tested PCIe NVMe SSDs.

IOMeter 512KB sequential write test with repeating data.

Sequential writing performance is also very important; and in this test sequential writing performance is measured.

The Toshiba OCZ RD400 M.2 NVMe SSD gave an excellent turn of speed in this test, and finished in second place.

512K sequential write – Queue depth profile

While most sequential writes will rarely rise above a queue depth of two, it has been noted from SATA analyzer traces that with more demanding tasks, queue depths can rise very close to a queue depth of four. This is why I now include queue depth profiles for sequential read and write.

512K sequential write – Queue depth profile

Below I present a table of the results in more detail.

IOMeter 512KB sequential write test with fully random data.

This test is almost exactly the same as the test above except that the test data is fully random in nature. This test was requested as SandForce based SSDs gain a lot of performance by being able to compress data on the fly. While the above test shows the SandForce based SSDs in a best case scenario, the following test will show the SandForce based SSDs in a more realistic light. In the real world, the data is neither 100% incompressible nor 100% compressible, it is somewhere in between. So please keep this in mind.

With data that is not so easy to compress, the SandForce SF-2282 based OCZ REVODrive 350 took a big performance hit, whilst the Toshiba OCZ RD400 M.2 NVMe SSD retains its writing performance, and finishes this test in top spot.

IOMeter 512KB sequential read test (dual threaded).

At a more realistic queue depth the Toshiba OCZ RD400 M.2 NVMe SSD is showing outstanding sequential reading performance, and finishes this test in first place.

512K sequential read – Queue depth profile

While most sequential reads will rarely rise above a queue depth of two, it has been noted from SATA analyzer traces that with more demanding tasks, queue depths can rise very close to a queue depth of four. This is why I now include queue depth profiles for sequential read and write.

Please note that in the following graph, I do not have the lowest possible score set at zero. This is purely to allow the graphs to be easier to read, but starting with a lowest possible score other than zero, gives the impression that there are large differences between competing SSDs with regard to performance, so please keep this in mind.

512K sequential read – Queue depth profile

Below I present a table of the results in greater detail.

IOMeter Workstation simulation (outstanding I/Os = 64).

When running applications you will find that there is a mixture of small random files and larger sequential files, being created and read. Not only that, it isn’t just one file at a time. In this test I measure a simulated workstation pattern, with a queue depth of 64 (threaded).

Toshiba OCZ RD400 M.2 NVMe 512GB SSD – Workstation simulation

The ‘workstation’ simulation sorts the men out from the boys, with its mixed reads and writes. This test shows how an SSD could behave with a heavy workload, in a graphics, or video workstation environment. The Toshiba OCZ RD400 M.2 NVMe SSD has excellent mixed read/write performance, and finishes the test in third place.

Summary

All in all, the Toshiba OCZ RD400 M.2 NVMe SSDs has performed extremely well in our IOMeter tests. The Toshiba OCZ RD400 M.2 NVMe SSD has outstanding reading performance, and writing performance is exceptional.

Now let’s head to the next page where we will look at how the Toshiba OCZ RD400 M.2 NVMe SSD performs using a new benchmarking application….